Researchers from Tel Aviv University and the Israel Institute for Biological Research have achieved a scientific breakthrough by developing the world's first mRNA vaccine effective against deadly bacteria, demonstrating 100% protection in laboratory animal studies. The vaccine represents a paradigm shift in infectious disease prevention, potentially offering a new weapon against the growing threat of antibiotic-resistant bacterial infections.
The study, published in Science Advances and led by Dr. Edo Kon and Prof. Dan Peer from Tel Aviv University's Laboratory of Precision Nano-Medicine, tested the novel vaccine against Yersinia pestis, the bacterium responsible for plague. In animal trials, all unvaccinated animals died within a week of infection, while those receiving the mRNA vaccine remained alive and well.
"Moreover, in one of our vaccination methods, one dose provided full protection just two weeks after it was administered," said Prof. Peer. "The ability to provide full protection with just one dose is crucial for protection against future outbreaks of fast-spreading bacterial pandemics."
Overcoming Biological Barriers
Until this study, scientists believed mRNA vaccines against bacteria were biologically impossible due to fundamental differences between viral and bacterial protein production. While viruses depend on host cells for reproduction, bacteria produce their own proteins independently, creating challenges for vaccine development.
"Since viruses produce their proteins inside our cells, the proteins translated from the viral genetic sequence are similar to those translated from the lab-synthesized mRNA," explained Dr. Kon. "Bacteria, however, are a whole different story: They don't need our cells to produce their own proteins."
Previous attempts to synthesize bacterial proteins in human cells resulted in low antibody responses and inadequate immune protection. The proteins underwent significant modifications, such as sugar additions, when secreted from human cells, reducing their effectiveness as vaccine targets.
Innovative Technical Solutions
The research team developed two breakthrough strategies to overcome these limitations. First, they bypassed the classical secretion pathways of bacterial proteins to ensure the immune system recognizes the vaccine proteins as immunogenic bacterial proteins. Second, they enhanced bacterial protein stability by combining it with sections of human protein to prevent rapid disintegration in the body.
"The result was a significant immune response, with the immune system identifying the proteins in the vaccine as immunogenic bacterial proteins," said Dr. Kon. "By combining the two breakthrough strategies we obtained a full immune response."
Addressing Antibiotic Resistance Crisis
The development comes at a critical time as antibiotic overuse has led many bacteria to develop resistance, posing a significant threat to global health. Prof. Peer emphasized that developing new vaccine types may provide an answer to this worldwide problem.
"It is important to note that the Covid-19 vaccine was developed so quickly because it relied on years of research on mRNA vaccines for similar viruses," Prof. Peer noted. "If tomorrow we face some kind of bacterial pandemic, our study will provide a pathway for quickly developing safe and effective mRNA vaccines."
The technology's rapid development potential mirrors the success of COVID-19 vaccines, which began clinical trials just 63 days after the SARS-CoV-2 genetic sequence was published. This speed advantage could prove crucial in responding to future bacterial outbreaks, particularly those involving antibiotic-resistant strains.
The researchers believe their new technology can enable rapid development of effective vaccines for various bacterial diseases, especially those caused by antibiotic-resistant bacteria, which represent an emerging pandemic threat requiring innovative therapeutic approaches.
